With the growth of mobile communication technologies and processor technologies, electronic devices (e.g., a mobile terminal device) may perform a great variety of functions beyond a traditional telephone function. For example, various applications such as an Internet browser, a game, and a calculator have been developed and used in electronic devices. As many functions have become available in electronic devices, security for information stored in the electronic devices has become more important. To meet such security needs, authentication techniques based on a user's biometric information are being developed.
Authentication techniques based on biometric information may include a process of acquiring a user's biometric information, e.g., information on a fingerprint, an iris, a voice, a face, or a blood vessel, and then comparing the acquired biometric information with preregistered biometric information to determine whether the user is an authenticated user. Among techniques based on the above exemplified biometric information, fingerprint recognition technique, for various reasons such as convenience, security, and economy, has been the technique most commercialized.
A biometric sensor such as a fingerprint sensor may be manufactured as a single module including a transmitter (e.g., an ultrasonic oscillator or an IR LED) and a receiver, and it may be embedded in an electronic device. The user may touch a part of the body to a portion of the electronic device such as a display, a button, or a housing, and the biometric sensor may acquire biometric information based on this touch.
Meanwhile, internal components of the electronic device may be changed in position because of a physical impact or other reasons while the electronic device is being used. The same may be applied to a case of the biometric sensor. In this case, it may be difficult to acquire accurate biometric information because of an unexpected change in position.